Roller bearing systems of the aforedescribed type (see German Patent document-Open Application 1,962,776) can be referred to as wire roller bearings because the actual running surfaces or races for the roller bodies are formed by a bed constituted by a plurality of wires which extend along the path of the roller bodies and are interposed between the roller bodies and the structural members of the bearing which are relatively displaceable.
The latter members may be rings in the case of a roller bearing in an annular configuration or may be bars in the case of a roller bearing used in a linear construction.
In conventional wire roller bearings, the wire races, hereinafter referred to also as running wires, are in direct engagement with the receiving structure, i.e. the structure forming the channel. In the latter document a liner of sorts is provided between the wires and the member.
In practice, the structure against which the running wires of the bed are braced determines the precision of the roller path and the quality of the bearing.
Defects in the fabrication of the support structure for the running wires of the bed or in the fabrication of the bed or the ability of the running wire bed to accommodate to the geometry of the support structure all have an adverse effect on the quality of the bearing.
Similarly, load and temperature effects which develop during operating act detrimentally on the bearing by deformation of the running wire bed because the running wires themselves have no significant intrinsic stiffness and hence the wire configuration is effected by these phenomenon which act upon the receiving structure.
Furthermore, in many cases the bed formed by the channel in which the running wires are provided are fabricated with different tolerances than that required by the running wire configuration so that the geometry at the contact zones of the running wires with this bed is not satisfactory.
For example, instead of large zones of contact between the wires and the supporting surfaces of the bed, the zones of contact may be small with high specific loading at the contact locations. This can result in critical deformations, setting characteristics and premature development of play depending upon the softness of the material from which the bed is constructed.
It has been proposed to overcome or reduce these drawbacks by providing increased areas of contact and thus better fitting of the parts together or by surface compaction or increased density of the contact surface between the bed and the running wires.
For bearing manufacturers with the knowhow to compensate for these drawbacks, this does not pose a problem although for others, especially those who may have to procure units formed by the running wires, the roller bodies and the roller cage, from the manufacturer and instal such units in bearings other than in the course of standardized bearing manufacture, the problems described can be insurmountable since similar knowhow is not available. As a consequence, in many cases inadequate bearing structures may be provided, defects in the bearings which are provided can arise and the developed response to the problems described cannot be adequately exploited.